today I noticed that my one bedroom central air register in the ceiling is dripping from condensation. The vent is in the closed position but when I open it I can feel a noticeable draft, either the flex line has a hole in it or its not attached to the register properly. All other vents are fine, I can open them and not feel any pressure changes, its only the one bedroom. My question other then checking the for obvious disconnection of the flex is, can I wrap addition bare fiberglass insulation around the register connection? or do I have a bigger issue that might require a new flex run with a higher r value?